BACKGROUND OF THE INVENTION
The present invention relates to a valve and a valved trocar jacket tube used in endoscopic surgery in pneumoperitoneum.
FIG. 1 shows a conventional valved trocar jacket tube wherein the valved trocar jacket tube 1 is composed of a cylindrical jacket 2 and a casing 3 secured to the top of the jacket 2. The casing 3 has a circular opening 3a on the upper part thereof. Furthermore, the casing 3 contains a valve 4 for opening and closing the opening 3a and a spring 5 for urging the valve 4 towards the closing direction therein.
In the case when the valved trocar jacket tube 1 thus constituted is employed, as shown in FIG. 2, a physician inserts the jacket 2 of the valved trocar tube 1 in a site, for example, the incised portion of the abdomen Pa of a patient P being an object to be operated. In case of using a clamp or the like, an adapter 6 being called by the name of reducer or introducer composed of a leakage preventing valve 6A having an opening 6a the inside diameter of which corresponds to the outside diameter of the clamp or the like and an outer cylinder 6B is employed. The physician sets the clamp or the like having a diameter corresponding to the diameter of the opening 6a of the adapter 6 thereto, and the clamp or the like so arranged is inserted through the opening 3a of the casing 3. In this case, the valve 4 is opened against the spring force of the spring 5 due to insertion of the adapter 6. As a result, leakage of an inert gas injected into an abdominal cavity for conducting easily endoscopy and the like is prevented.
According to the conventional valved trocar jacket tube 1, however, there is such a problem that since the diameter of the opening 3a defined on the casing 3 is stationary, it is required to use an adapter 6 having the diameter corresponding to that of the clamp or the like 7 to be employed on all such occasions, and such substituting operation required incidentally is troublesome, so that the operator""s manipulation is prevented.
Furthermore, there are such problems that since any contour in the opening 6a of an adapter 6 is circular the contour of a clamp or the like 7 is limited to that having a circular shape and that since the standard sizes in the opening 6a of an adapter 6 are usually 5, 10, and 12 mm, a clamp or the like 7 having an intermediate size such as 6 mm or 8 mm cannot be used, so that sizes of the clamp or the like 7 are also restricted.
Besides, since the inside diameters in the openings 6a of adapters 6 and the outside diameters of clamps or the like are nominal values, respectively, there are such problems, that the inside: diameter of an adapter 6 does not match with the outside diameter of a clamp or the like 7 in reality, and as a result, either such clamp or the like 7 is impossible to uses or there is a case of arising leakage.
Accordingly, an object of the present invention is to provide a valve and a valved trocar jacket tube by which the use of an adapter becomes unnecessary, types of clamps and the like to be employed are not limited, and the leakage of an inert gas from an abdominal cavity can be prevented.
According to the first feature of the present invention, a valve disposed on the trocar jacket tube mounted to the incised portion of a diseased part, comprises a pair of rings placed oppositely in a coaxial state and a cylindrical elastic member the ends of which are attached respectively to said pair of rings and having an opening of a prescribed sectional area; said elastic member having such structure that when said pair of rings are rotated relatively in the opposite directions at a predetermined angle, said opening changes the sectional area between a closed state and a state of said prescribed sectional area in response to said predetermined angle.
According to the above described constitution, when the pair of rings are relatively rotated in the opposite directions at a predetermined angle from the state where the opening of the elastic member has been closed, the opening of the elastic member is opened. In case of employing a clamp or the like, it is inserted into an abdominal cavity through the above described opened opening. Since the elastic member has elasticity, the opening is close together with the clamp or the like inserted.
According to the second feature of the present invention, a valved trocar jacket tube mounted to the incised portion of a diseased part, comprises a pair of rings placed oppositely in a coaxial state; and a cylindrical elastic member the ends of which are attached respectively to said pair of rings and having an opening of a prescribed sectional area; said elastic member being provided with a valve having such structure that when said pair of rings are rotated relatively in the opposite directions at a predetermined angle, said opening changes the sectional area between a closed state and a state of said prescribed sectional area in response to said predetermined angle and a jacket means attached to either ring of said pair of rings and being inserted into said incised portion of the diseased part to maintain the same in an opened state.